Retort muffler

ABSTRACT

A muffler for sound attenuation of steam exhausting from retorts comprising a cylinder having end perforations and an internal pipe diffuser together with drain holes for draining condensed moisture so as to minimize corrosion is provided.

United States Patent 1191 1111 3,858,677 Bussey 1 Jan. 7, 1975 1 RETORT MUFFLER 2,940,300 6/1960 Loving 73/35 2,998,860 9/1961 Everett 181/35 R [751 lnvemor- R01) L Bussey Alamo cahf' 3,114,431 12/1963 Sanders 181/36 13 73 Assignee; The Clorox Company Oakland 3,117,650 1/1964 Ludiow 181/36 B Calif 3,145,800 8/1964 Marx 181/45 3,311,189 3/1961 Powers 181/35 R [22] Filed: Aug. 9, 1973 3,491,850 1/1970 Neitner 181/35 R [21] Appl. N0.: 386,969

Primary Examiner-Rwhard B. W11k1ns0n Assistant Examiner-Vit W. Miska U-S. Cl. B, Altorney Agent r Moore [5 Int. Cl- \Neigsenbergg Lempio & Strabala [58] Field of Search 181/35 R, 35 A-35 C, 181/36 R, 36 A-36 D, 37, 43, 45, 47, 54, 59,

72; 126/85 [57] ABSTRACT A muffler for sound attenuation of steam exhausting 1 1 References Clted from retorts comprising a cylinder having end perfora- UNITED STATES PATENTS tions and an internal pipe diffuser together with drain 2,072,372 3/1937 Kingsley 181/36 R holes for draining Condensed moisture S0 118 to mini- 2,138,510 11/1938 Rauen 181/36 B mile Corrosion is Provided 2,531,139 11/1950 Lilly 126/85 2,735,504 2/1956 Moyer 181/36 R 1 Clam, 11 Drawmg F'gures ,-,'0'- Z 4 1Q: 4. 68 44 4 '11- n 72 it s I 4 \\\\\1 I PATENTED 7 sum 2 or 5 PATENTEUJAN W5 3. 858.677

SHEET 3 OF 3 nr/ ms NS 1 v A m GI wI \w m? MW BACKGROUND OF THE INVENTION This invention relates to mufflers for use in attenuating the sound of steam escaping from a pressure vessel. More particularly, this invention relates to mufflers for use on vents and bleeders of large cooking retorts as found in the canning industry.

Currently, in the canning industry, large pressure ves sels or retorts are used for batch processing of canned food under steam pressure. The process typically involves admitting pressurized steam to a large tank or retort containing a batch of containers in the form of cans of food to be processed. The steam enters the bottom of the retort through an inlet line and is distributed by means of a steam spreader manifold extending along the bottom of the retort. The steam rises around the cans and is exhausted through a vent so as to remove air from the retort before starting the timing of the process. The vent is typically a valve controlled opening in the tank and may also include a vent line. During the thus-described come-up period, the temperature in the retort rises until a predetermined, desired temperature is reached. At this point, the vent valve is closed and the retort temperature is maintained at a desired value by means of an automatic steam controller which includes a control valve in the inlet line.

The retort also typically includes bleeders in the form of smallorifices of the order of %3% inch I.D. which are placed so as to ensure exhaustion of air entrained with entering steam. Valves such as petcocks may also be added for use in selectively closing off the orifices when processing glass containers. The bleeders are also placed at the top of thermometer wells so as to provide steam circulation around thermometer bulbs in the wells and thereby ensure accurate readings. The bleeders are open during the entire process for metal containers even though the vent is closed after come-up as will be hereinafter described. The bleeders are closed when processing glass containers as aforementioned.

After the process time has elapsed, the vent is opened and steam is discharged to the ambient surrounds. This venting of the retort is referred to as the come-down period. During an entire process cycle, including come-up process, and come-down periods, steam escaping to the ambient surrounds through the vent and bleeders creates a sound so loud as to be a potential hazard to the hearing of human operators in the vicinity of the retort.

The thus-described problem of excess noise inherent with the operation of retorts in the canning industry has become especially acute with the passage of the Occupational Health and Safety Act (OHSA), setting limits on noise levels in industrial contexts. Thus, in addition to general desirability, there is a statutorily imposed requirement of sound attenuation affecting such retorts. Addition of sound attenuation devices in the form of mufflers attempts to solve the basic problem while perhaps creating other subsidiary problems. One such subsidiary problem is that of corrosion caused by the wet steam and condensation which may block the mufflers and consequently upset the thermal processes in the retort which may result in improperly cooked food. Also resultant from this corrosion problem is the necessity of frequent and costly inspection and replacement of the corroded mufflers. Another problem is that the mufflers should not obstruct steam flow since to do so would increase back pressure and might upset the process. Also, since the operator should have visual indication of steam flow through the bleeders and vents at all times for proper process control, the muffler should not mask or obscure the flow viewability.

SUMMARY AND OBJECTS OF THE INVENTION It is in an attempt to solve some or all of the above problems that the following disclosed invention is directed. The invention takes the form of an improved muffler for sound attenuation of steam escaping from a retort as used in processing canned food. The muffler in various forms is effective in achieving approximately 10-1 1 dB,, noise reduction on retort bleeders and 21-22 dB,, noise reduction on vents, so as to bring them within levels specified by the OHSA. The inventive muffler basically comprises a generally cylindrical body closed at both ends and having a perforated diffuser tube extending therein through one end thereof with additional perforations in the other end thereof. Provi sion is made for mounting the muffler on a petcock or valve on a retort top bleeder opening or on bleeder or vent lines.

It is therefore the primary object of this invention to provide a muffler which effectively attenuates the sound of steam escaping from retorts.

It is also an object of this invention to provide such a muffler which is both corrosion-resistant as well as inexpensive to produce.

It is also an object of this invention to provide a muffler which is resistant to damage and yet is easily installed or removed.

It is a further object of this invention to provide such a muffler which attenuates sound and does not mask or undesirably obscure the escaping steam from view.

It is still another object of this invention to provide such a muffler which does not increase back pressure in the retort and thus upset the thermal process.

These and other objects and advantages will be more readily apparent by having reference to the following description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a retort, partially broken away for purposes of clarity, having vent and bleeder mufflers mounted thereon;

FIG. 2 is an enlarged cross sectional, elevational view of a top bleeder muffler from FIG. 1;

FIG. 3 is a top plan view of the same;

FIG. 4 is an enlarged cross sectional, elevational view of an alternate embodiment of the muffler of FIG. 2;

FIG. 5 is a partial view in cross section of yet another alternate embodiment of the same;

FIG. 6 is an enlarged cross sectional, elevational view of a vent muffler from FIG. 1;

FIG. 7 is an end view of the same illustrating the end perforation configuration taken in the direction 7-7 in FIG. 6;

FIG. 8 is a view of the same illustrating an alternate end perforation configuration;

FIG. 9 is an enlarged corss sectional, elevational view of a thermometer well bleeder muffler from FIG. 1;

FIG. 10 is an end view of the same illustrating the end perforation configuration taken in the direction 10-10 in FIG. 9; and

FIG. 11 is a view of the same illustrating an alternate configuration.

Detailed Description Turning to FIG. 1, there is shown generally at a large retort comprising a cylindrical body portion 12, a closed bottom end 14, and a domed top cover or closure 16. The top cover 16 is removable for admitting cans or jars of food to be processed to the retort chamber 18. Steam from a steam source (not shown) is fed into the retort through an inlet line 20 by means of an automatic steam controller including a control valve (not shown). Steam is distributed within the chamber 18 by means of a spreader 22 having a plurality of perforations therein. After rising in the chamber, the

steam passes out through a top bleeder 24 in the form of an opening in the top cover which may also include a petcock. The sound of the steam escaping from the top bleeder is attenuated by a top bleeder muffler 26 as will be hereinafter described.

Projecting from the body is a thermometer well 28 having a thermometer 30 mounted thereon. Also located on the well is a thermometer well bleeder 32 in the form of an opening which has mounted thereon a thermometer well bleeder muffler 34 as will also be hereinafter described.

An' outlet or vent line 36 having an outlet valve 38 therein allows rapid discharge of steam from the retort through a vent 40 in the form of an opening in the retort body top. A vent muffler 42 is mounted on the end of the vent line for attenuating the sound of escaping steam.

With particular reference to FIGS. 2 and 3, there is shown a top bleeder muffler 26 mounted on retort top cover 16. The top bleeder muffler comprises a hollow, cylindrical body 44 having top and bottom end closures 46, 48, respectively. The body may be conveniently made from a 3-inch I.D. standard steel pipe nipple 5 inches long. The top end closure 46 can be a 3-inch I.D. standard steel pipe cap threadedly secured to the cylindrical body end so as to permit easy access to the cylinder chamber 50. Bottom end closure 48 having a cen- I tral aperture 52 therethrough is recessed so as to permit fitting over the threaded outlet 54 of petcock 56. Bottom end closure 48 is conveniently made from a inch thick steel plate tack welded to the cylinder interior wall to allow for drainage of condensed steam. The A: inch l.D. petcock is left in the open position during the process cycle and is used to maintain a /8 inch orifice for a bleeder function. The valve stem 58 is extended through a sidewall cutout to form a slot 60 to allow manual operation thereof. Projecting into the cylinder from the bottom end closure 48 is a hollow, cylindrical pipe diffuser 62 having an open outer end 64 and a closed inner end 66. The diffuser has a plurality of holes or perforations 68 ranged along its length so as to laterally direct the steam into chamber 50. It has been found that a It; inch I.D. standard steel pipe nipple 2% inches long having nine A; inch diameter holes in three 120 groupings along the diffuser achieves satisfactory noise attenuation when coupled with perforations in the top end closure 46 on a A inch diameter bleeder.

These latter perforations have been satisfactorily found to comprise eight 6 inch diameter, equally spaced holes 70 with four on a 1 inch diameter and four on a 2% inch diameter hole circle.

A A; inch I.D. pipe coupling 72 having an OD. greater than central aperture 52 may be threaded onto threaded outlet 54 so as to secure the muffler to the retort. The muffler will be thus rigidly secured along a nearly circumferential rim 73. Alternatively, the central aperture 52' may be sized so as to encompass coupling 72 and be fixed thereto as shown in the alternate embodiment of FIG. 4. 7

Since the top bleeder muffler is subject to mechanical abuse from overhead movement of retort crates, the particular muffler design shown wherein the base rim 73 contacts the domed retort top cover 16 over almost a 360 line of contact is advantageous. The arrangement also protects petcock 56 (or alternatively conduit 74) from damage if hit from any direction yet provides a muffler that is easily installed or removed.

In another embodiment shown in FIG. 5, the petcock is eliminated and replaced by a conduit 74 such as a /6 inch I.D. steel pipe coupling 1% inches long. This embodiment also illustrates the use of a A; inch pipe cap as an end closure for closed end 66'.

Turning to FIG. 6, there is shown the constructional features of vent muffler 42. The generally cylindrical body 76 is closed at opposite ends thereof byv end closures 78, 80, so as to define a chamber 82 therein. Projecting into the cylinder and closely fitted through an aperture in end closure 78 is a cylindrical pipe diffuser 84 having a plurality of holes or perforations 86 therein. The chamber end of the diffuser is obturated by fixing same to the chamber side of end closure 80. The opposite end has threads 88 thereon for attachment to a vent line. As best seen in FIG. 7, end wall has a plurality of holes or perforations 90 therein for escaping steam. An additional drain hole 92 is also provided at the lower edge of end closure 80 to allow drainage of condensation and thereby reduce the likelihood of corrosion of the muffler. Alternatively, a hole configuration such as shown in FIG. 8 may be provided wherein a plurality of drain holes 92' are spaced around the peripheral edge of end closure 80 so that drainage will take place regardless of the rotational orientation of the cylinder. It may be noted that these drain holes 92' also serve the dual purpose of drainage and venting, thus fewer vent holes 90 are required.

An effective vent muffler for use with a 1% inch diameter vent line may be made by using a body 76 of 12 inch diameter by 30 inch long schedule 40 black iron pipe with end closures 78, 80 of A inch thick steel plate. Diffuser 84 may be conveniently 2 inch diameter by 36 inch long schedule 40 black iron pipe. Holes 86 may be of inch diameter drilled through at 3 inch intervals along the pipe from alternate 180 directions. Holes 90 may be inch diameter with four on a 4 inch diameter and eight on an 8 inch diameter hole circle. In the alternative embodiment, the 8 inch diameter hole circle is replaced by eight "/3 inch drainage holes 92.

Turning to FIGS. 9-11, thermometer well bleeder muffler 34 for use with a Vs inch diameter bleeder may conveniently have a cylindrical body made from 2 inch diameter standard pipe of 9 inch length. End closures 96, 98 may be made from 3/16 inch thick steel plate. Drainage holes 97, 99 of Vs inch diameter are located at each end of the body 94. Pipe diffuser 100 is 4; inch [.D. standard steel pipe 8 inches long. Holes 102 of Va inch diameter are drilled through at five places at "9 1 inch intervals along the pipe. Eight Va inch diameter holes 104 are equally spaced on a 1 /2 inch diameter hold circle. Alternatively, these may be replaced by 3/16 inch diameter equally spaced around the periphcry of end closure 96. It may be noted that stainless steel or other corrosion and heat resistant material may be used for all or selected parts of the above-described mufflers where corrosion is a special problem.

It is to be understood that the foregoing description is merely illustrative of preferred embodiments of the invention and that the scope of the invention is not to be limited thereto, but is to be determined by the scope of the appended claims.

What is claimed is:

l. A retort muffler comprising a generally cylindrical hollow body portion defining first and second open ends, said first open end defining a circumferential base rim adapted for contacting a mounting surface, a first imperforate end closure closing said first open end and being spaced therefrom, a second end closure closing said second open end, so as to define a chamber within said body, said second end closure comprising a cupshaped cap threadedly secured to said body, a single aperture in said first end closure, a generally cylindrical, hollow elongated diffuser member defining inner and outer open ends extending through said aperture and into said chamber, said inner end of said diffuser being spaced from said second end closure means closing said inner end of said diffuser, means defining a plurality of holes in said diffuser member, said plurality of holes in said diffuser member being spaced along said diffuser member, means defining a plurality of holes equally spaced around a hole circle of constant diameter in said second end closure, said plurality of holes in said second end closure being un-obturated so as to intercommunicate said chamber with the exterior of said body portion and thereby to the atmosphere, a valve having an elongated stem substantially included between said first end closure and said first open end, an elongated slot in said body between said end closure and said first open end, and wherein said valve includes an alongated valve stem extending through said slot,

* l l l Dedication 3,858,677.R0be1"t J. Bussey, Alamo, Calif. RETORT MUFFLER. Patent dated J an. 7 1975. Dedication filed Feb. 10, 197 5, by the assignee, The 6701-000 Company. Hereby dedicates to the Public the entire remaining term of said patent.

[Ofiicz'al Gazette June 24, 1975.]

Dedication 3,858,677.R0bert J. Bussey, Alamo, Calif. RETORT MUFFLER. Patent dated Jan. 7, 1975. Dedication filed Feb. 10, 197 5, by the assignee, The

010mm Oompomy. Hereby dedicates to the Public the entire remaining term 01": said patent.

[Oficial Gazette June 24, 1.975.] 

1. A retort muffler comprising a generally cylindrical hollow body portion defining first and second open ends, said first open end defining a circumferential base rim adapted for contacting a mounting surface, a first imperforate end closure closing said first open end and being spaced therefrom, a second end closure closing said second open end, so as to define a chamber within said body, said second end closure comprising a cup-shaped cap threadedly secured to said body, a single aperture in said first end closure, a generally cylindrical, hollow elongated diffuser member defining inner and outer open ends extending through said aperture and into said chamber, said inner end of said diffuser being spaced from said second end closure means closing said inner end of said diffuser, means defining a plurality of holes in said diffuser member, said plurality of holes in said diffuser member being spaced along said diffuser member, means defining a plurality of holes equally spaced around a hole circle of constant diameter in said second end closure, said plurality of holes in said second end closure being un-obturated so as to intercommunicate said chamber with the exterior of said body portion and thereby to the atmosphere, a valve having an elongated stem substantially included between said first end closure and said first open end, an elongated slot in said body between said end closure and said first open end, and wherein said valve includes an alongated valve stem extending through said slot. 